Propiolic acid
Propiolic acid
Names
Preferred IUPAC name
Other names
Propiolic acid Acetylene carboxylic acid Propargylic acid Acetylene mono-carboxylic acid
Identifiers
878176
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard
100.006.763
EC Number
81893
KEGG
MeSH
C011537
UNII
InChI=1S/C3H2O2/c1-2-3(4)5/h1H,(H,4,5)
N Key: UORVCLMRJXCDCP-UHFFFAOYSA-N
N InChI=1/C3H2O2/c1-2-3(4)5/h1H,(H,4,5)
Key: UORVCLMRJXCDCP-UHFFFAOYAX
Properties
C 3 H 2 O 2
Molar mass
70.047 g·mol−1
Density
1.1325 g/cm3
Melting point
9 °C (48 °F; 282 K)
Boiling point
144 °C (291 °F; 417 K) (decomposes)
Acidity (pK a )
pk a = 1.89 [2]
Hazards
GHS labelling :[3]
Danger
H226 , H301 , H310 , H315 , H335
P210 , P233 , P240 , P241 , P242 , P243 , P261 , P262 , P264 , P270 , P271 , P280 , P301+P310 , P302+P350 , P302+P352 , P303+P361+P353 , P304+P340 , P310 , P312 , P321 , P322 , P330 , P332+P313 , P361 , P362 , P363 , P370+P378 , P403+P233 , P403+P235 , P405 , P501
Safety data sheet (SDS)
External MSDS
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
Chemical compound
Propiolic acid is the organic compound with the formula HC2 CO2 H. It is the simplest acetylenic carboxylic acid . It is a colourless liquid that crystallises to give silky crystals. Near its boiling point, it decomposes.
It is soluble in water and possesses an odor like that of acetic acid .[4] [5]
Preparation
It is prepared commercially by oxidizing propargyl alcohol at a lead electrode.[6] It can also be prepared by decarboxylation of acetylenedicarboxylic acid .
Reactions and applications
Exposure to sunlight converts it into trimesic acid (benzene-1,3,5-tricarboxylic acid).[5] It undergoes bromination to give dibromoacrylic acid. With hydrogen chloride it forms chloroacrylic acid. Its ethyl ester condenses with hydrazine to form pyrazolone .[5]
It forms a characteristic explosive solid upon treatment to its aqueous solution with ammoniacal silver nitrate .[5] An amorphous explosive precipitate forms with ammoniacal cuprous chloride .
Propiolates
Propiolates are esters or salts of propiolic acid. Common examples include methyl propiolate and ethyl propiolate .
See also
References